1. Field of the Invention
The invention relates to sequencing methods that permit direct detection of nucleic acid fragments on a sequencing gel. More specifically, silver staining can be used to stain the sequencing gel and thereby provide a record of the nucleic acid fragments for sequence determination.
2. Background Art
Prior art sequencing methods utilize radioactive or fluorescent labels to visualize DNA fragments to determine the sequence of the nucleic acid. Some prior art methods have used biotin labeled DNA for chemical sequencing, and involve transfer of the DNA from the gel to a membrane, which is not only cumbersome but also expensive (the large size membranes required for handling sequencing gels are expensive). The present method of affinity purification of the fragments is rapid and avoids the need for transfer to a membrane while providing a permanent record of a silver stained gel.